What causes the empty stomach pain while lying down for a few hours, especially when you wake up at night but are still in lying down?

Not very clear about your diagnosis as it needs examination and sometimes tests also. However, your description of pain in lower abdomen in early morning(=empty stomach) can be because of full urinary bladder or abdomen full of gases. When you get up and move, gases are passed. You urinate and empty the bladder. It relieves pain. It can be because of piles or gastric ulcer as you suspected but less likely as pain is relieved by just getting up and moving.

Your stomach is producing more acid than it should. Make a routine of drinking some thing soothing and cool, atleast once a day. You can have buttermilk, honey-water, saunf(in hindi). And drink lots of water. Avoid too spicy intake and stop drinking tea. You'll get better soon. My mother too suffered from the same.. These will work.

Go with the diagnosis pf doctor..and as of ulcer pain it usually occurs in upper part of abdomen in centre usually..and yeah it is aggravated by spicy and oily foods..therefore it is unlikely to be of gaatric ulcer. Rest consult your doc!